Description
This platinum silicone mold rubber is mixed in a 1A:1B ratio by volume, eliminating the need for a weighing scale. It has a low viscosity, so vacuum degassing is not required for most applications. The material has a Shore hardness of 30A.
Features
- Cures to soft, strong, tear-resistant rubbers.
- Exhibits very low long-term shrinkage.
- Suitable for casting wax, gypsum, resins, and other materials.
- Heat resistant up to 232°C (450°F).
- Can be used for casting low-temperature melt metal alloys.
- Not intended for brush-on moldmaking.
- Will not cure against surfaces containing sulfur, even when sealed.
Technical Properties
- Mix Ratio By Volume: 1A:1B
- Mix Ratio By Weight: 100A:96B
- Pot Life: 45 minutes
- Cure Time: 6 hours
- Shore Hardness: 30A
- Specific Gravity: 1.12 g/cc
- Specific Volume: 0.89 cm³/g
- Tensile Strength: 2.9 MPa (420 psi)
- 100% Modulus: 662 kPa (96 psi)
- Elongation @ Break: 339%
- Die B Tear Strength: 15.4 kN/m (88 pli)
- Color: Blue
- Useful Temperature (max): 232°C (450°F)
- Useful Temperature (min): -54°C (-65°F)
- Mixed Viscosity: 12,500 cps
Instructions
Safety
Use in a well-ventilated area. Wear safety glasses, long sleeves, and rubber gloves. Use vinyl gloves only, as latex gloves will inhibit curing. Store and use at room temperature (23°C/73°F). Warmer temperatures reduce working and cure time and shorten shelf life.
Cure Inhibition
Silicone rubber may be inhibited by contaminants, resulting in tackiness or lack of cure. Latex, sulfur clays, certain woods, and newly cast polyester, epoxy, or urethane rubber may cause inhibition. Test compatibility by applying a small amount of rubber to a non-critical area. If inhibition occurs, apply a clear acrylic lacquer to the model surface and allow it to dry thoroughly before applying rubber.
Because no two applications are quite the same, a small test application to determine suitability for your project is recommended if performance of this material is in question.
Note: Even with a sealer, platinum silicones will not work with modeling clays containing heavy amounts of sulfur. Do a small scale test for compatibility before using on your project.
Applying A Release Agent
A release agent can make demolding easier. Ease Release™ 200 is recommended for silicone. Test suitability with a small application if performance is in question.
Measuring & Mixing
Pre-mix Part A and Part B separately. Dispense required amounts into a mixing container (1A:1B by volume) and mix thoroughly, scraping sides and bottom. The rubber should be a uniform color with no streaks.
Optional: Vacuum Degassing
Vacuum degassing helps eliminate entrapped air. Vacuum material for 2-3 minutes at 29 inches of mercury, leaving room for expansion.
Pouring
Pour mixture in a single spot at the lowest point of the containment field. Let the rubber seek its own level to minimize entrapped air. The liquid rubber should level off at least 1.3 cm (1/2 inch) over the highest point of the model surface.
Curing
Allow to cure for 6 hours at room temperature (23°C/73°F) before demolding.
Heat Curing
Reduce demold time by applying mild heat. For example, place the mold in a hot box or oven at 60°C (140°F) to reduce demold time for a 1.3 cm (1/2 inch) thick section to about 10 minutes. Time varies with thickness. Use Plat-Cat™ cure accelerator to reduce demold time or Slo-Jo™ cure retarder to extend pot life and cure times. Do not cure below 18°C (65°F).
Mold Performance & Storage
The mold's life depends on use. Casting abrasive materials erodes detail, while non-abrasive materials like wax do not. Clean molds with soap and dry before storing. Assemble multi-part molds and store on a level surface in a cool, dry environment.
